Without limiting the scope of the invention, its background is described in connection with the isolation, characterization and use of human transcription factors that are expressed throughout the organism, as an example.
Unlike the nucleic acid polymerases of prokaryotes, purified RNA polymerase II from eukaryotes initiates transcription very poorly and essentially at random. One key difference between prokaryotic and eukaryotic polymerases is the need for accessory factors that provide for the accurate initiation of transcription. These factors are referred to as the “general” or “basal” transcription factors, in that they are required, in addition to RNA polymerase II, for the transcription of all eukaryotic protein coding genes. As such, the general transcription factors are expected to be active, or at least present, in all or most tissues. One such general factor is called transcription factor IID (TFIID) and is responsible in large part for promoter recognition. Other general transcription factors include TFIIA, TFIIB, TFIIE, TFIIF and TFIIH.
Appropriate levels of gene and tissue-specific transcription is achieved by another set of factors called activator proteins. These factors are often composed of two domains, a sequence-specific DNA recognition domain and an activation domain. When bound to DNA, the activation domain facilitates the formation and function of a preinitiation complex that consists of the general transcription factors and RNA polymerase II. In this way it is possible to direct the selective transcription of genes in an appropriately regulated fashion.
The structure of a typical promoter for a eukaryotic gene consists of two general regions. The core promoter is located at or near the actual site of transcription initiation and often includes a TATA sequence element located at about 30 base pairs upstream of the initiation site. The other regions are defined as sequence elements which are recognized by activator proteins. These are often located at various distances further upstream, but may be also be located downstream relative to the core promoter of the gene being regulated. Interactions between bound regulatory factors and the preinitiation complex are responsible for the precisely regulated transcription of each individual gene.
TFIIA is an essential general transcription factor and the purified factor from higher eukaryotes consists of three subunits, designated alpha (35 kD), beta (19 kD) and gamma (12 kD). In humans, the alpha and beta subunits are encoded by DNA sequences present in the TFIIAα/β cDNA, sometimes referred to as the ‘large’ subunit cDNA. These two subunits are post-translationally processed from a large 55 kD product of TFIIAα/β. The gamma subunit is encoded by DNA sequences present in the TFIIAγ cDNA, sometimes referred to as the ‘small’ subunit cDNA. This sequence is the subject of U.S. Pat. No. 5,562,117 issued to Moore and Rosen. TFIIA has multiple roles in transcription initiation by RNA polymerase II, including an ability to stabilize TBP-TATA element interactions, displace TBP-associated repressors and serve as a cofactor during the processes of transcription activation.
Most of the known human general transcription factors appear to be generally required in all tissues for gene expression by RNA polymerase II. Thus, these factors will be important as markers to evaluate disease states which may arise from inappropriately regulated gene expression and as pharmacological reagents and/or targets with which to modulate patterns of gene expression. Similarly, overexpression via gene therapy or other means should have broad effects on the expression of many or all cellular genes. In contrast, mutations in the genes for activator proteins, which are normally observed to control expression of a select set of genes, often in a tissue or developmentally restricted pattern, typically result in specific defects. Likewise, overexpression of activator proteins only affects expression of cellular genes which contain cognate recognition sequences.
Testis has important endocrine (hormonal) functions and is the site for the production of haploid spermatozoa from undifferentiated stem cells, a process called spermatogenesis. Mutations in some specialized transcription activator proteins, such as A-myb and CREM, cause male infertility and show defects in spermatogenesis. The identification of tissue-specific human general transcription factor would bridge an important gap between the generality for general transcription factor function and the specificity of gene-specific transcription activator protein function. If such factors were testis-specific, they would be expected to regulate patterns of gene expression that are important in the endocrine, spermatogenic and other functions of this organ. The present invention satisfies a need in the art for new compositions for polynucleotide sequences and encoded polypeptide products, immunological reagents and other derived materials in terms of providing unique reagents for the detection of defects in testis function such as idiopathic male infertility or other syndromes, for detection of dysfunctional patterns of gene expression and as reagents that can modulate gene expression.